Oracle (ORCL -4.01%) stock tumbled 5% through 11 a.m. Is Oracle stock still a buy? I suspect this is the detail that's giving investors pause today. Absent an outright sale, Oracle should insist on at least a full source code license giving it full access to the TikTok algorithm's underlying codebase. Anything less than that, and Oracle stock is probably not worth its present 75 times earnings valuation.